Published on 07/22/96

Japanese Beetles Attacking in North Georgia

One day rose bushes look healthy and beautiful with abundant, lush green leaves. The next time you look, there's nothing left to the leaves but veins.

There is a likely villain: Japanese beetles.

"The Japanese beetle population fluctuates from year to year, and this year seems to be bad one," said Beverly Sparks, an entomologist with the University of Georgia Extension Service.

The beetles are a bigger problem in north Georgia than in other parts of the state.

"We have Japanese beetles in most counties in Georgia, but they reach much higher numbers in the north," Sparks said. "They haven't reached pest proportions in the southern counties yet."

Georgia is home to several kinds of beetles, but the destructive Japanese variety is easy to spot.

"They're easy to identify because of their striking color pattern," Sparks said.

The thumbnail-sized beetles are metallic green with copper- colored wings. They have a row of five spots on each side of their abdomen.

Their attack may not be limited to roses.

"They have a host plant range that goes on forever," Sparks said.

"They feed on a wide variety of plant material, including roses, crape myrtles, apples and plums, to name a few," she said. "As a matter of fact, I saw some feeding on kudzu the other day."

Japanese beetles generally feed on leaf tissue between the veins. So after they feed, the veins are all that remain.

There's not much you can do to prevent Japanese beetles except move out of their range, Sparks said.

"It's hard to prevent them because they fly and migrate to host areas with desirable plants," she said. "They will still migrate from other areas even if you treat your yard."

During the adult stage, when Japanese beetles are in active flight, it helps to treat the plants they like to feed on with an insecticide. Sparks recommends Sevin.

"However, you will have to repeat the applications as long as the adults are active, usually for six to eight weeks," she said. "How often you need to reapply really depends on the weather."

If it rains or if the insecticide breaks down fast, reapply accordingly.

"Commercially available beetle traps are very effective in telling you when the adults are present," Sparks said. "But I wouldn't use them as a control technique."

The traps contain a pheromone that attracts beetles and calls them into the trap.

"You know if they're present, but you are actually attracting beetles to the area. So," Sparks joked, "if you use a beetle trap, put it in your neighbor's yard."

Faith Peppers is the director of public affairs with the University of Georgia College of Agricultural and Environmental Sciences.